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Cold Malt Extraction


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So making tasty normal beer is not exactly difficult and I feel the need for a challenge. Am also enjoying the lack of alcohol. 

I want to try to make a really tasty beer at well under 2% ABV. There's many different techniques that commercial breweries (including Coopers) employ, but the one I think might work well is documented here at Briess: http://blog.brewingwithbriess.com/cold-extraction-of-malt-components-and-their-use-in-brewing-applications/

The trick is that you extract 90% of grain flavour and body / mouthfeel but only extract 25% of the fermentables. 

I think my Aramis Pils up next should be a good candidate. Normally I would be brewing it as a 1.050 OG, 50 IBU beer, but this time I'll be using the same amount of grain to get maybe a 1.020 OG beer and adjust the bittering to get about 27 IBU. Same late and dry hopping for that lovely herbal and lemon Aramis character. 

Process:

  • 6:00am - Add grain to cold Canberra tap water in my cooler mash tun
  • 8:00pm - run off (no sparge) into my kettle, raise to 67C and mash for an hour
  • Boil / hop / no-chill in the kettle as normal

Aiming for 11l of 1.020 SG wort in the fermenter from 3kg Gladfield pils malt and 18l cold strike water. I do have some Vienna and Munich lying around to, but think I'll stick to a SMaSH beer this time. 

Hopping

  • 5g Aramis at FWH 
  • 30g Aramis at 10 mins
  • 30g Aramis at flameout
  • 30g Aramis dry hop

Fermented with Wyeast 2278 slurry.

Cheers, 

John 

Edited by porschemad911
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This time I'm not going to do anything with the fermentables left in the extracted malt.

If I was really a glutton for punishment and up for a very long evening I could always treat it as adjunct sugar (since most of the character is gone), add more malt and heated strike water and do a second mash.

This second mash could produce a lighter-bodied bigger beer, eg something like a Brut IPA, Belgian Tripel or Golden Strong or maybe even a Double IPA.

Maybe another time... 

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2 hours ago, porschemad911 said:

Maybe another time...

Hi John

Care to go into what you might do in more detail if you could do this second batch. It sounds interesting. Two brews from one and a bit lots of grain. 

Cheers Shamus

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2 hours ago, Shamus O'Sean said:

Hi John

Care to go into what you might do in more detail if you could do this second batch. It sounds interesting. Two brews from one and a bit lots of grain. 

Cheers Shamus

Sure thing Shamus.

Well there would be enough fermentables left in the original grain bill to get roughly 11 litres of 1.030 wort into the fermenter. However I need more grain to provide diastatic power, flavour and body. If I added say another 3kg high D.P. grain to that mash plus extra strike water, that might bring it up to 11 litres in the fermenter of something like a low to mid 1.070s OG.

The exact calcs are a little complicated. There's maybe 4.5l of 1.017 SG wort trapped in the grain and in dead-space on my system, maybe 50% expected extract yield left in the grain from the cold extract soak, say 85% expected yield from the freshly added grain. Put it all together and I think the result would be roughly as above.

Cheers,

John

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Interesting concept.

Sounds similar, but opposite, to first and second runnings.

I will keep an eye on how your brew goes. 

I have done some high alcohol beers, but because I cannot drink six of them in a night I am looking at what can I do at mid range alcohol levels, but good flavour.  Some of @Beerlust's ideas have been an inspiration.

Cheers Shamus

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54 minutes ago, Shamus O'Sean said:

Some of @Beerlust's ideas have been an inspiration. 

Yep that's his wheelhouse, nicely balanced beers around 5% ABV. I brewed an all-grain conversion of his Mosaic Amber Ale recipe a few years back now. It was a really nice beer, very well balanced with good malt flavours and nice complimentary hopping.

So that one's worth a go! 

Cheers, 

John 

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Doughed in at just before 6 this morning before a nice cool ride into work. The infusion temp was at 12C after mixing nice cold tap water, so I added some ice to bring it down further. Trying to avoid it warming up too much during the day and getting any lacto activity.

DSC_0152.JPG

Cheers, 

John

Edit: As you can see, 3kg pils malt and 18l water leaves plenty of room in my 38l mash tun. 

Edited by porschemad911
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Well that is a strangely high OG reading.

DSC_0154.JPG

I suspect due to the fine crush on these grains (sourced from ibrew a while back), a lot of fine starch came over in the runnings as flour and got converted in the mash step. It made for a tricky lauter and a very milky runnings. 

DSC_0153.JPG

It was fascinating watching it clear as conversion happened.

See how things go through the ferment, I'm wondering what the FG will be. Wort looks and tastes great, more grain flavour than usual for sure. 

Cheers, 

John

Edited by porschemad911
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Does the hydrometer read 1.050? And you were aiming for 1.020? Something seems to have gone wrong. 😧 

Experimenting is interesting. You'll have to do it again to try to try and figure it out.

Wonder if that flour is giving you a falsely high hydrometer reading, meaning maybe it did not convert but it is just adding to the density of the solution? A hydrometer doesn't just measure sugar, it actually measures density. This can happen when working with fresh fruit too, and that is why they recommend putting the juice through a coffee filter before taking a reading. Fruit solids can add 2 Brix to a reading. It varies from one fruit to the other.

Cheers,

Christina.

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Yes I expected around 1.020 OG and measured 1.042.

I am wondering the same thing with the flour @ChristinaS1. That's why I'm also very curious about the measured FG, although I won't be able to tell how much of the drop is due to flour settling out and how much is due to fermentation. I suppose I'll have to guess at the ABV from how it feels when drinking.

Something felt wrong when lautering. Briess say the run-off should be faster and easier than with a hot mash, but for me it was much slower and more difficult. 

Anyway, it is fermenting well at 11C at the moment. It took around 48 hours to develop a krausen, which I attribute to the low 10C pitching temp and the fact that the harvested slurry was in the fridge for 5-6 weeks. I pitched around 300ml thick slurry which should be plenty.

I will be trying this technique again next batch, although I'm not quite sure what I will brew. I have a bit of Vienna and Munich to use up, so I'm leaning towards attempting a lower ABV version of a Doppelbock with this method (grain bill for a 1.080 OG). I will buy grain from my LHBS this time, which has a coarser crush and less flour. 

Cheers, 

John 

 

Edited by porschemad911
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Judging by the clarity of the sample it got converted pretty well, if it didn't then it would be still cloudy. I remember getting similarly milky wort when I tried doughing in at around 40 degrees on a batch a few years ago, but it too largely cleared up when it was mashed. Seems to me that the milky stuff is starch rather than flour.. flour would drop out pretty quickly and not really affect the SG reading unless there was a large layer at the bottom. 

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@porschemad911 I finally got around to reading the article on cold malt extraction. It reminds me that Mary Anne Gruber of Briess began popularizing the notion of cold steeping black patent for a smoother / less roasty / less astringent flavour around 20 years ago. Sounds like Briess have been continuing to explore the possibilities of cold brewing. 

Trying to figure out why your OG was so much higher than expected. They talked about a "standard" recipe with OG of 1.050 resulting in a 1.0-1.5% ABV beer, but they don't define "standard." Elsewhere they employed an Amber Ale recipe. Maybe they assume a "standard recipe" has ~10-30% non- and low diastatic malts, whereas you used 100% base malt. Do you suppose that is playing a role? I was also wonder if you stuck to the 4L/kg water to grain ratio indicated in the article? 

Finally, I wonder what temperature they used for conversion, and how long did they let it rest? They don't provide any details regarding this.

Cheers,

Christina.

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John, you probably saw this reddit post by a guy who made a saison using the cold extraction method:

I found his use of CaCl interesting. But apparently he did not let his wort rest at mash temperature, he just brought it up to a boil. You think that would be wrong, leaving behind too much unconverted starch, but on the other hand there isn't a lot of unconverted starch in a cold extracted wort to begin with, so I don't know.

I wonder if it would make sense to write to Briess and ask them what conversion protocol they used? 

Anyone have a subscription to BYO magazine, or want to sign up for a 14 day free trial? Apparently Michael Tonsmeire touched on the subject of cold extraction brewing in this article: 

https://byo.com/article/brewing-table-beer/

Cheers,

Christina.

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4 minutes ago, ChristinaS1 said:

Hey John, just to clarify, was that reading taken pre-boil or post boil? Thanks. 

Christina.

Hi Christina,

1.042 was the post-boil SG, sample cooled to room temp. The pre-boil sample read 1.03x but I didn't trust it very much because of all the particulate.

The yeast seem to be liking it! I'm letting it slowly rise to 15C (now at 12C with a heap of activity). I'm still detecting a slightly grainier smell than usual, but see how that changes after fermentation. 

Cheers, 

John 

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Just reading Michael Tonsmeir's Twitter feed and he mentions he rested a cold extracted ESB wort at 160F / 71C for conversion, which is kind of high. It is the beer he later wrote about for the BYO magazine article. In the comments someone mentioned that they had tried making two cold extracted brews, one a Pilsner and one a Doppelbock. You and he think alike John! 😆 He said both had a unique, very strong malt character coming out of the keg, but they did not take well to bottling (very susceptible to oxidation). Interesting. Maybe a reason to include some oats in the recipe?

Cheers,

Christina.

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Interesting. I started my mash rest at 65C, then brought it up to 67C after it had dropped down to 64C (around half an hour later). 

Haha, good to hear someone has successfully done a Doppelbock this way! 

Why do you suggest oats to combat oxidation? 

Cheers, 

John 

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Scott Janish looked at a number of studies about brewing with oats and a few showed anti-staling effects.

http://scottjanish.com/case-brewing-oats/

Those studies were done using large percentages (20-40%) of oats. I would not want to go that high myself, but 10% couldn't hurt.

Not sure how cold mashing would impact their anti-staling properties.

Cheers,

Christina.

PS Doesn't Clarity Ferm also improve beer stability? Or maybe that is just colloidal stability....Not sure if it fights oxidation.

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I wrote Dan Bies at Briess, author of the abstract, and asked him if they did a conversion rest. He wrote back and said, "We did ~30min stand at 152°F," while heating the wort to the boil. He actually felt this length of time was excessive. 152F = 66.7C.

Cheers,

Christina. 

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14 hours ago, ChristinaS1 said:

I wrote Dan Bies at Briess, author of the abstract, and asked him if they did a conversion rest. He wrote back and said, "We did ~30min stand at 152°F," while heating the wort to the boil. He actually felt this length of time was excessive. 152F = 66.7C.

Cheers,

Christina. 

Thank you very much for passing that on! For my next attempt I will try heating the runnings to 67C, resting for 20 mins, then heating to a boil.

Did Dan mention anything about the overnight steep time / temp? I did around 14 hours at 10 - 11C. Perhaps this was too long and too warm. I can use a big block of ice to drop the temp right down if need be, although shortening the time is tricky. 

I dry hopped the beer today. It had dropped bright already so I will give it another week then bottle. Despite the high ABV (around 4.3% bottle conditioned) it smells and tastes great. 

Cheers, 

John 

Edited by porschemad911
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